


Sammy, Let me go (I can't)

by professorandre1228



Series: Winchesters and the Avengers [3]
Category: Supernatural, The Avengers (Marvel Movies), The Avengers (Marvel) - All Media Types
Genre: It's NOT just a car, how to cure a demon
Language: English
Status: Completed
Published: 2020-02-29
Updated: 2020-03-13
Packaged: 2021-02-28 05:28:44
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 7
Words: 13,983
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22958704
Author URL: https://archiveofourown.org/users/professorandre1228/pseuds/professorandre1228
Summary: The Mark of Cain has turned Dean into a Demon and as much as the Winchesters hate dragging their new superhero team friends into their world, Sam, in a moment of weakness, calls Natasha.  Kevin has been murdered by the angels, Cas is missing, and Dean is dead.And Sam is desperately seeking Crowley to get his brother back. Clint, Tony, and Thor rush to his aide.
Series: Winchesters and the Avengers [3]
Series URL: https://archiveofourown.org/series/1527761
Comments: 9
Kudos: 80





	1. A Mark on the Soul

**Author's Note:**

> Thanks for your patience on part 3 finally coming together. First attempt was rushed and non-organic. I think I've finally found my feet again and welcome any and all open criticism.

“Sam?” Steve looked over upon hearing Natasha say the name after answering her phone. He gave her a questioning look and she shrugged. 

At first, there was no sound except hitched breaths.

“Sam? What’s going on? Are you okay?” She asked around the lump in her throat. 

“Tash. They’re all gone,” was the broken reply. Sam’s voice was soft but cracked and raw. Natasha’s breath caught and she closed her eyes.

“Gone? Gone where?” She didn’t really want to ask but needed to know.

“The angels killed Kevin.” Sam said softly before swallowing audibly. “Cas disappeared after he went to Heaven to stop Metaton. And…,” he sobbed once, “Dean’s dead and his body is missing.” At that point, he devolved into broken sobbing. Tears prickled Nat’s eyes as she pictured Sam huddled alone and shaking in the dark bunker with no one there to see him.

“Oh my god, Sam,” she breathed out. “Are you going to be okay?” There was more sobbing but it softened as he tried to calm himself. She knew he was only calling because he was desperate as he’d never willingly pull any of them into the Winchester’s problems if it could be avoided. She was hoping that the situation with SHIELD and the Winter Soldier could be resolved soon enough for her to get there and hold him through his sorrow.

“No. No, I’m not,” Sam cried as he hung up the phone. He hung his head between his knees and let the wail of anguish escape as he sat on the edge of Dean’s bed.

Natasha gasped and immediately dialed her phone for the only person she could think of who could help right now, understanding that she was too far away and too wrapped up into the current situation to be able to help. When the other side answered, her voice was not as steady as she would have liked.

“I’m sorry to throw this at you, but Sam needs help. Now.”


	2. The Knight Brought Low

**Summary for the Chapter:**

> Dean is captured.

“At the end of the, sir, we have to strategically calibrate expectations. And so, by making these 64 small changes, I believe we can increase our demon-conversion rate by 0.03%.” The androgynous man reading out the report to Crowley as he sat, hands tapping the tumbler of whiskey, failed to note that the King of Hell was tense and bored. A dangerous combination. Luckily, the man’s phone rang before he could say anything else that would add to Crowley’s frustration. He listened, frowning, before pocketing the phone in one of the suit pockets. “Uh, sir? Sir?”

Crowley rolled his eyes around to look at the man/demon expectantly.

“Kill me.” As he said it, the demon addressing him wasn’t sure it was a request or an aside, so he paused only a second before laboring on.

“Uh, sir. It’s Sam Winchester, sir. He’s getting close.” Crowley’s eyebrows rose and his hands paused from the tapping, but before he could make any other response, the back door of the bar opened and Dean Winchester, still dressed in jeans, work boots, and flannel, entered. Both the demons standing behind Crowley tensed and the King’s eyes narrowed, watching as Dean casually poured himself a drink before dropping into the seat next to him.

“Well? How did it go?” Dean shrugged and took a long swallow of his drink.

“Fine, fine. Uh, he’s dead. And you’re right. I…I feel amazing.” Dean smiled darkly as he drank down the rest of what he had poured and then sat the tumbler down on the table, purposefully flexing his forearm, watching the red Mark move over his muscles.

Crowley leaned forward, turning his head fully towards Dean.

“He? What do you mean, he?” Dean smirked, then got up to pour himself another drink, this time remaining at the bar, with the bottle sat within reach.

“Lester.” Crowley immediately sat up straight, the boredom being replaced with anger. The demons behind him swallowed anxiously and glanced at each other.

“The client? You killed the client?” Dean shrugged one shoulder this time and turned to face Crowley, leaning back against the bar with the elbow not holding his drink.

“Does it matter? He was a douche. Now he’s a dead douche.” Crowley stood up, knocking the chair back, his face going red. The only one who didn’t flinch was Dean. 

“Of course it matters!” Crowley took a step towards him, hands flexing as he became more animated. Dean took another swallow. “The deal was one dead wife for one soul.” The King of Hell held up one finger in emphasis. “The wife’s not dead so I don’t get the soul.” He changed the one finger, added his thumb and it became a zero. “It’s math.” Dean shrugged again, draining the tumbler. Then he turned at the waist to set it on the bar, and started towards the barroom door again.

“Well, there you go,” was all he said. Crowley stalked towards the older Winchester brother, raising his hand as though to grab at his shoulder.

“Hey! Don’t you turn your back on me!” His hand never landed though because Dean swiftly turned on the ball of his foot and threw the arm with the Mark on it towards the dapper demon, sending him sprawling backwards, ending up on his ass and back on the floor. Dean chuckled coldly down at him. One of the demons snorted, then tried to cover it with a cough. Crowley’s head swiveled.

“Is something funny?” The demons both went very still and serious, shaking their heads.

“No sir,” the one who snorted said instantly. Crowley ungracefully picked himself up off the floor, dusting off his suit, pulling it to straighten it.

“Good.” He stared hard at Dean now. “What do you think you’re doing?” Dean chuffed and his eyes flickered from the emerald green he was known for, to the tarry black of his new demon soul. 

“Oh,” he said, his voice low and dark, “Whatever I want.” The other demons tried to fade into the background, but the King of Hell stalked towards him slowly.

“Really? Because I think you don’t know what you want. Tell me, Dean. What are you?” Dean blinked, his eyes narrowing. “Are you a demon? If so, why isn’t Lester’s wife dead? Did you feel sorry for her?” Dean snarled at him. “So maybe you’re a human. Except you have those pretty black peepers and you’re working alongside me. Why don’t you do us all a great big favor and PICK A BLOODY SIDE?!” The last was shouted as he poked Dean’s chest. When Dean bowed up at him, balling up his fists, Crowley pulled his hand back.

“Or what? Hmmm? Go ahead. Make a move. See how it ends.” Crowley cleared his throat but didn’t make any further gestures. “I ain’t your friggin’ bestie, and I ain’t takin’ orders from you. When I need to kill, I’ll call. Until then, stay out of my way.” He turned to stalk away, waving his arm as if dismissing them all. Crowley pulled his lapels straight, then pulled on the cuffs of his jacket and shirt.

“Fine.” Dean paused but didn’t turn back. “It’s over. What can I say? Crazy ones-, well, they’re good for a fling, but they’re not relationship material.” Crowley smirked back over his shoulder at his demon minions. Dean turned his head to only catch him in his periphery.

“Are you done?” 

“Oh, we’re done.” Crowley shoved his hands into his pants pockets. “You know what, Dean? It’s not me. It’s you.” 

“Oh, it’s definitely both of you,” a new voice said, catching them both off guard. They all whirled around, catching sight of the Iron Man suit sliding in behind the bar, Dean pulling out the First Blade from where it had been tucked into the back of his jeans. The superhero suit settled and the faceplate folded back, revealing Tony Stark, who now opened a bottle to sniff the contents before pouring himself a drink in a clean glass. The two demons started towards him but Crowley put up an arm to stop them and they paused. Crowley’s eyes narrowed.

“Mr. Stark, to what do we owe this pleasure?” Tony took a sip, then tilted his head, eyes looking up as though considering the drink. It apparently wasn’t rotgut so he poured some more and put down the bottle.

“Definitely your pleasure, not mine.” He said, eyes flickering cautiously between Dean and Crowley. He slid around the end of the bar into the wider bar room area where the rest stood watching him with. “Dean.” He said, nodding congenially to the black-eyed brother of his friend. 

“Sam sent…you? To save…me?” Dean smirked, gesturing to Tony, then to himself with the blade. 

“Saved me a bloody phone call,” Crowley muttered. Dean and Tony glanced over at him. Tony gave the demon a confused look then turned his attention to Dean.

“Sort of and no and yes. Sam called Widow and she called Jarvis, which kind of hurt my feelings. She sends her regards, by the way, but to save you?” Tony gestured with the empty hand in the so-so movement. “To capture you, definitely. Save you? That’s something Sam will have to handle.”

“Well, I’ll take my leave now. Tell Bullwinkle I’ll be in touch.” They both looked at Crowley with disbelief just as he and his minions poofed out. Dean shook his head in disgust, before turning back to Iron Man.

“I told Sam to let me go.”

“And you know I can’t do that.” Dean swiveled his eyes to the side and back before turning to face Sam, the taller man standing just inside the doorway, his arm in a sling. Dean sat partially on the table he was closest to and scoffed.

“Who winged ya?” Sam rolled that shoulder with a wince.

“Does it matter?” Dean shrugged.

“Not really.” He stood and stalked towards Sam. Sam threw up his good arm in defense and braced his knees. Tony sat the glass down quickly, ready to intervene.

“Dean, hold on a second. You don’t have to do this. Look, we know how to cure demons. You remember that?” Dean paused and scoffed again. Tony swallowed and held his position.

“Little Latin, lot of blood. It rings a bell. Did you ever stop to think that if I wanted to be cured, I wouldn’t have bailed?” Sam shook his head.

“That was Crowley.” Sam shook his head again, his hazel eyes not really believing. Dean’s face contorted into something dark and dreadful as he smiled at his painfully optimistic brother.

“It really wasn’t.” Sam glanced over his brother’s shoulder at Tony, who gave a minute shake of his head. Then he looked back at Dean, desperation seeping into his voice.

“It doesn’t matter, all right? ‘Cause whatever went own, whatever happened, we will fix it.” Dean focused completely on the man in front of him.

“Will we? ‘Cause right now, I’m doing all I can not to come over there and rip your throat out…with my teeth. I’m giving you a chance Sam. You should really take it.” He smirked and slid the blade back into his waistband, as if it weren’t a consideration, and Tony could feel the coiled energy boiling from the man/demon in front of him.

“Any time now, Legolas,” Tony muttered quietly. Dean’s eyes flicked back behind him for a split second before dismissing the dark haired man. 

“I’m gonna have to pass.” Sam’s reply to Dean’s offer was quiet, but heartfelt. Dean’s eyes blinked back to green.

“Well, I’m not walking out that door with you. I’m just not. So, what’re you gonna do? You gonna kill me?” Dean threw out his empty hands to his sides. Sam’s face contorted with horror and sadness and he dropped the hand he was still holding up, as though he had been reaching for his brother.

“No.” Dean tilted his head in consideration.

“Why? You don’t know what I’ve done. I might have it coming.” Sam shook his head, feeling the hot prickle of tears behind his eyes.

“I don’t care. Because you’re my brother and I’m here to take you home.” Dean leaned his head back and laughed. Sam and Tony swallowed, their eyes meeting briefly in fear.

“Ah! ‘You’re my brother and I’m here to take you home.’” He said mockingly, lilting his voice like he used to when teasing his little brother. “Yeah, what is this, a Lifetime movie? Huh? With your puppy-dog eyes? And injured paw?” He laughed louder, leaning down to slap his knee and mockingly wipe his eyes as thought it had been hilarious. Sam’s face fell but he stood taller. “Oh, thanks, Sammy. I needed that.” Sam pulled out the sigil-etched handcuffs from his back pocket. Dean gave another scoff. “You really think those are gonna work on me?”

Sam squared his shoulders and gripped the cuffs a little tighter, hearing the connecting chain clink.

“There’s one way to find out.” And just as Sam and Dean took a step towards each other, the glass window to the left and behind Sam shattered and Dean staggered back as something thunked into his shoulder. Sam gasped, stumbling, nearly dropping the cuffs. Dean looked down at his shoulder, seeing the arrow sticking out, then up at Sam in disbelief, then out the broken window, knowing Hawkeye was out there, even if he couldn’t see him. 

Dean roared, his eyes changing back to black and he charged at Sam, throwing a one-two knockout punch combination, dropping the tall man. Sam had just hit the ground, unconscious, when the second arrow thunked into his back and Tony muttered a curse, throwing his faceplate back on. He rushed towards Sam, watching Dean throw open the door to run outside, looking for Clint. 

“Heads up, Clint, he’s still up and he’s out for your blood.” Tony alerted Clint over the comms inside the suit as Jarvis scanned Sam and let him know that the younger man was only unconscious, not dead. “He dropped Sam, but kid’s okay, just down for now. I’ve got the cuffs.” Tony patted Sam’s shoulder gently, then pulled the cuffs from his lax hand and followed Dean’s exit. 

“I got him in my sights, Tone,” Clint’s voice came back to him as he scanned for Dean in the parking lot. “He’s heading my way. He’s staggering but still coming. I’ve got one more tranq arrow and then I’ll have to resort to less subtle means.” Tony swiveled his head towards where Jarvis indicated his GPS and sure enough, there was Dean, staggering and lurching as he half ran that way. He was bouncing off the side of the few cars in the lot, but didn’t appear to be going down any time soon.

Jarvis told them both that most likely Dean’s demon side was fiercely fighting the tranquilizers, but a shot of holy water might slow him down enough that it allowed the tranqs to work. Both of them had seen how demons reacted to holy water but if it was their best chance…

“Do it, Clint.” His visor caught the glint of the arrow as it streaked from the roof the building a block or so away and saw Dean stumble as it hit him. Iron Man lifted off to give chase, keeping back from Dean enough to let Clint’s long-range tactics have a chance to bring him down safely. He’d rather not be heavy handed with Sam’s brother.

Clint had the last tranq arrow nocked and ready to release when Dean finally stumbled onto his knees, then his hands, still crawling forward, his black eyes locked onto where the archer was most likely firing from. 

Iron Man landed just behind the crawling man, watching as he turned his head to roar at him before he fell forward and fell unconscious. The area went quiet, Jarvis conveying his caution that the vitals of a demon were not in his databank so he could not confirm he was truly out cold or just playing to lure them in. Iron Man gave it a full two minutes before he leaned forward and turned Dean over. The arrows the demon had pulled out on his own during his traipse but sensors and instinct made Tony take a deep breath.

“Target is down.” Kneeling next to Dean, he snapped the handcuffs around his wrists and then pulled the pliant body up and over his shoulder to carry back to their transport. “Clint, can you check on Sam in the bar while I secure the dead man?” He got an affirmative and Jarvis alerted him of the gps movement. He gripped his cargo and lifted off.

Landing at the quinjet, parked in the public park a little bit away, he laid Dean on the fold out table that had held his dying brother once upon a clandestine chance ago and secured him with the strong but small chains that had been especially designed for securing the Hulk. He left Jarvis to monitor the unconscious man and returned to the bar to meet up with Sam and Clint.

Clint had Sam sat up against the wall, with an ampule of something under his nose, and his other hand on Sam’s good shoulder. Tony landed just as Sam lurched, flailing back to awareness.

“Easy, kid,” Clint said, pulling the ampule back, tossing it unerringly into the trashcan 20 or so feet away. Sam groaned and reached up to rub his jaw while looking around.

“Dean?” Tony reached down to offer him his hand to help him up, while Clint stood on his side to offer support as he rose.

“Tranq’d and chained up on the jet with those sigil etched cuffs. You okay?” Sam took a deep, shuddering breath, then nodded jerkily.

“Yeah. Yeah, I’m good. Let’s get Dean back to the bunker.” Sam squared his shoulders, stalking out of the bar. Clint and Tony glanced at each other with concern, but followed him. Sam paused in the parking lot, spying the Impala. She was filthy and from what he could see, trash littered the dashboard and most likely the seats and floorboards. He huffed, blinking his eyes rapidly, then continued on to the jet. Tony caught the disturbed look and followed the gaze to the car. Clint did as well and he flinched hard. If there was anything truly telling about how Dean wasn’t himself, the state of his prized possession said it all. 

“Once we get this all straightened out, I’ll come back for Baby,” Clint offered as he jogged to catch up to Sam’s long legs. Sam didn’t glance around but nodded in gratitude, his eyes infinitely sad. 


	3. Not Quite the Reunion Tony Had Envisioned

**Summary for the Chapter:**

> Recap of between Part 2 and Part 3. Cure ritual begins.

Once in the jet, Sam sat in the seat previously used by Bruce when Sam had been the one strapped to the table. He ran his good hand through his hair as he leaned forward, one knee jumping with nerves. Tony and Clint shared a concerned glance, but then Clint shrugged one shoulder and went to the cockpit while Tony closed the rampway. And off they went.

Not much later, they landed in the same clearing the Avengers had first used when visiting the hunters’ lair. The clearing had been cleaned up to make the trip easier for them all so there was less to trip on. After their first clandestine encounter, all of the tower residents had taken a keen interest in learning more about the Winchesters’ history beyond the broad outline that had been shared during the interrogations and they had each read the Carver Edlund book series, as well as gotten some filled in blanks from other conversations with Sam, Dean, Cas, and Kevin.

If the broad outline had shaken them, the deeper dive had blown them away. Dean and Sam had shared what they could but as Clint had explained once to Dean that he couldn’t share everything about the Avengers or SHIELD, Dean and Sam had replied how some of their history was best as ONLY a broad outline and too much information wouldn’t be good for any of them. 

Sam had spent most of the trip reaching over and touching Dean like he was reassuring himself that he was real. Tony had watched him do it again and again, trying not to blatantly stare. After learning about ‘hallucifer’ time, as the internet fans had clamored about, they had asked about and investigated Sam’s time of mental institutionalization. And honestly, watching Sam tentatively reaching out again and again, only to pull his hand back and then rub the palm of his hand absentmindedly, Tony could see the connection, but knew better than to comment. It was something that kept Sam grounded, and by the look of the tall hunter, he needed something right now to ground him hard. 

The Winchester brothers had expressed their desire to not drag anyone else into their issues unless it was world-ending and had no other way. Thus, the Avengers had known about Metatron and the angels, mostly from their first encounter after the Trials, and how Crowley had tricked Dean into taking on the Mark of Cain as the only way to kill Metatron. Dean, during any real off time, liked to come and hang with Clint and Thor for some fun or adventures. Cas did come occasionally to work with Thor on the issue of the angels and Metatron, but they more often met at the bunker and then flitted between Asgard and Earth. Kevin, though, felt really out of place around the Avengers so he spent most of his time at the bunker. Whenever any of the three came to the tower, they used one of the guest rooms.

Sam, however, had his own set of rooms at the tower since he had become a part time consultant and research assistant to Tony Stark and Bruce Banner. When he wasn’t able to come, he spent time online with Tony and Bruce, working with them on the ‘monster’s compendium’, or other projects that either of them liked to bring him into. He helped them research other scientific subjects, such as helping Bruce put together the paper for the formula used to save Sam’s life. Whenever he could though, all of them knew he’d spend private time with Natasha. 

The two of them were adorable together. They were touchy-feely, always holding hands or leaning against the other and the smiles came easier to both when they were together. But when professionalism was needed, neither of them had a problem slipping into their respective hunter or spy mode. Dean had told them that Sam slept better, with less nightmares, when Natasha visited them in the bunker or met them in a hotel elsewhere. Clint had said the same for Natasha. The couple took their share of ribbing and jokes as the tallest and shortest members of both teams and as the only couple, although Dean and Cas took some ribbing of their own as everyone joked about their true bromance. Sam still blushed as some of the jokes were quite ribald or obscene, but most were kept clean or unspoken because Natasha’s threatening looks even withered Thor. That didn’t change the fact that everyone was also fiercely happy for both of them and protective of them and their time together.

When Sam had finally broken down, calling Natasha for help, they were all shocked. Natasha and Steve were, unfortunately, caught up in the Winter Soldier hunt and the Hydra/SHIELD conspiracy, so she had alerted Jarvis to bring together whatever help Sam needed. Thor had found Cas after he and the other angels and captured and imprisoned Metatron in Heaven. Then, Thor and Cas had left on a quest to another area of the nine realms in search of a rare potion that could simulate and/or restore angel grace, knowing that Cas would be no help in saving Dean without grace. Several of his fellow angels had offered some of their grace to sustain him but most of them were still hunting him or just fighting amongst themselves, so Asgard was looking for an alternative. Bruce had gone to India to help sort out an epidemic, similar to the one he’d been working when Natasha had found him before the battle of New York, and his new formula was proving to be effective in the treatment but he was invaluable and thus unable to break away at the moment. That left Clint and Tony, who were more than happy to jump and run to Sam’s side.

After phoning Sam for a breakdown of what was going on, they had taken the jet without delay and on the way, looked into the incidences that had led up to this point. They’d seen the reports on the news of the ‘angel’ calling himself Marv, whom Cas had confirmed before was really Metatron. He was publicly healing people. Tony had Jarvis looking for Dean in public feeds and had only found him once, on a video feed from a few days ago, following Marv into an abandoned commercial area, with old warehouses that now only held homeless people. Sam hadn’t been far behind, but the only ones to come out had been Sam, carrying what appeared to be an unconscious (Tony now knew it was ‘dead’) Dean back to the Impala. Sam had placed Dean into the back seat and then driven away. Tony had picked up the car arriving back at the bunker and Sam carrying his brother (the body) inside. 

Jarvis had reported that Dean’s cell phone was still active, but the GPS had been disabled and even tracking via cell tower usage was useless as it appeared to switch around the country within minutes. There was no way that was reliable. They knew the King of Hell could teleport so perhaps he was teleporting Dean along with him. That made this way harder. 

It was actually Sam who had picked up Dean’s trail, while looking into demon signs and weird police reports to try to track down Crowley to get Dean’s body back, as, up until that point, he’d thought the King of Hell had just had a demon installed to steal the body. He had actually been traumatized to learn that the demon inside of Dean was in fact Dean himself, not a demon posing as him. The report had actually shown a demon attacking Dean in a convenience store and Dean taking him out. Sam had gotten ahold of the attacker’s cell phone, redialing the last number, and not shockingly, Crowley had answered. 

That, along with Jarvis’s help, they’d tracked Crowley and Dean to the bar, where they had converged to bring their boy home. 

Once landed, Tony hauled the cuffed and still unconscious Demon Dean, or Deanmon, as Clint called him off-handedly before they met up with Sam, not that either of them would say that to Sam’s face, into the bunker. Directly to the dungeon, where Sam had him placed in the chair in the center of the seal of Solomon, cuffed to the chair, then tied so he couldn’t move. As he started coming around, he was huffing and chuffing, reminding Tony and Clint of Sigourney Weaver’s possessed character floating above her bed in Ghostbusters. Again, they were neither one going to ever say something like that to Sam while he was so upset. Maybe after Dean was human again, but not now. 

They could both see that Sam had lost weight as his clothes hung on him and he definitely appeared to take up less space, even for his 6’5” height. His hair was lank and stringy and his face gaunt and hollow. Even his eyes were dark around them as though he hadn’t slept for weeks. They had both seen him when Dean had brought him into their midst after the Trials and they’d seen him after, once they’d begun working together and all of them were healing mentally and physically. And this, this was worse than the Trials. This was one step away from kamikaze. 

Clint stayed in the dungeon with Dean while Tony escorted Sam to a local blood bank, where the young man used his SHIELD ID to confiscate enough blood in Dean’s type for the demon curing ritual, then to a church, where Sam dressed as a doctor to get the blood blessed, with a vague story about the blessed blood will be used during a transfusion. Tony was stunned with how easy he had been believed, at how easy he had fallen into the roles he played, even looking exhausted and utterly drained. But as they had all learned: ‘anything for my brother.’

Upon returning to the bunker, Sam had insisted on carrying the medical transport cooler himself into the dungeon, setting it on the table, while Dean watched him with a smirk. Clint was leaning against the dungeon wall, outside of the circle and appearing nonchalant, but Tony knew that look by now and Clint was anything except casual. He was on watch, hands never far from a blunt weapon, or from the tranq gun holstered to his thigh. Natasha would harm him irreparably if he accidently killed her boyfriend’s brother. And Clint wasn’t too keen on having to hurt his new buddy either. 

Dean scoffed when he saw Sam pulled out the rolled up tool cloth, each slot holding a large syringe filled with blood.

“For whatever it’s worth,” Sam said tiredly, keeping his back to Dean while he laid the roll out, “I got your blood type.”

“Sam,” came the reply and the tone was so cold, so unlike the Dean they had come to know, that all three of them flinched, Clint’s nearly imperceptible. “I know you think you’re gonna try and fix me, but did it ever occur to you that maybe I don’t want to be fixed?” Sam’s eyes came up from the table and he heaved a shuddering breath. Dean’s lip curled up in a mocking smile. “Just let me go live my life. I won’t bother you. What do you care?” Sam looked down again as he reached into the cooler and pulled out a flask. He turned to eye his brother. Dean’s eyes were still green, but where Sam looked like only his own will was holding him upright, Dean’s skin was healthy and tanned, his hair neatly trimmed and brushed back. He looked for all the world as though he had just come home from a long vacation at the beach, well fed and well rested, with not a care in the world.

“What do I care?” The taller man splashed the holy water from the flask onto Dean, watching him flinch and howl with pain as it burned him and he snarled. Clint stood a little straighter and Tony, still wearing his Iron Man suit, barely stopped himself from staggering backwards. Sam splashed more on the floor and began the demon cure ritual with the latin intonation. 

“You think I’m just gonna sit here like Crowley? Getting all weepy while you shoot me up? Well, screw this. I don’t want this!” He tugged at the ropes binding him and leaned forward to growl at his brother. 

“Yeah,” came Sam’s response, sounding for all the world, like it pained him to speak at all. “I pretty much figured that out.” Dean growled again, but leaned back. 

“You don’t even know if this is gonna work, do you? You know, I got a hell of a lot more running through me than just demon juice.” He flexed his exposed forearm, emphasizing his point. At this point, Tony spoke up, trying to provide emotional support as well.

“Mark of Cain, I think we got that,” he said. Dean turned his head to smirk at the billionaire, eyes flickering in Clint’s direction and then dismissing him. While that may have happened to Clint before, this time, it unnerved him and Tony could tell, but the archer was not broadcasting it like anyone else would.

“That’s right. Aren’t you special coming to Sammy’s rescue? You and your play pals think you can do anything except hold his hand?” 

“We brought you down, didn’t we?” Tony’s voice was confident even if he wasn’t. Dean nodded and looked down with a chuckle. 

“Well, that was in the open and when I wasn’t looking. Shame, shame.” He turned his icy stare onto Clint, who stared right back, face blank of emotion. “Like we talked about before, it’s not a weapon for close up work and this qualifies as close, don’t you think?” He looked around pointedly, then turned his gaze back on Sam, who had pulled out one of the syringes and walking towards him. “Sammy, you know I hate shots.”

Sam stopped just short of the chair, then splashed him with holy water again. Dean roared an unearthly howl as his skin sizzled, his eyes flicked to black, and it was just enough of a distraction that he closed the distance and buried the needle in his forearm, very close to the red Mark of Cain, and pressed the plunger. 

“And I hate demons.” Sam pulled out the needle and backed off immediately. “Look. We got a whole bunch more of these go to. You could make it a lot easier on yourself.” Dean’s smirk and composure dropped as something started happening that he wasn’t expecting and they could tell. He grunted and groaned, feeling the blood already having some effect on him. 


	4. A Brotherly Moment Too Close to Home for Some

Hours passed and syringes were emptied. Tony had only ever been on the receiving end of torture so being on this side of it was making him twitch. Because, to him, while it appeared the cure was working, it was clearly torturing Dean and by proxy, Sam, although the first was physical, the latter mental. Tony had broken out into a sweat, not due to the temperature in the room, as the bunker was underground and the dungeon was cooler than any other area within. When Sam had quietly told Tony to take a break as it would take a long time to get where they needed to, his friend had wanted to argue that Sam needed a break too, but knew it was pointless. 

So Tony had glanced at Clint, who had barely nodded at him, conveying in that one gesture that he was okay and would stay with Sam and Dean. That had the catalyst to get him moving, stepping out of the suit, leaving it by the door to the dungeon so he could quickly step back into it if he was needed. The goatee’d man had held himself steady until he’d turned the first corner, then stumbled against the wall. It was a moment of two before he caught his breath and rolled his shoulders, gathering himself now that he was out of the oppressive atmosphere where his young friend and his demon brother faced off. 

In an effort to ground himself, he walked the hallways, heading for the kitchen, preparing to make some coffee for them all. When he at first passed Sam’s room, he paused and turned back, sighing as he pushed the door open and peered inside cautiously. If anything said something about Sam’s current state of mind, that would do it. Sam was meticulous with his research and kept his areas neat and clean. To see the bed unmade, all the dirty clothes scattered on the floor, and half empty coffee cups along the dresser and desk, told the Avenger that Sam was only focused on Dean and nothing else mattered. And from his experience, that meant that Sam was most likely neglecting himself as well, as Tony was wont to do when he worried over others. He stepped inside and piled up the dirty clothes against one wall, not seeing a hamper, and gathered up the dirty coffee cups to return to the kitchen.

He sighed, then pulled the door closed, and headed for the kitchen. Here, it was pristine. There was nothing out of place that he could tell. Of course, the kitchen was Dean’s domain, so most likely, the quiet giant was only venturing in for coffee, not wanting to make a mess or move anything, so Dean would be happy when he returned. That explained why all the dirty coffee cups were in Sam’s room, instead of being returned to the kitchen, which Tony now sat in the deep sink. 

He started the coffee pot, leaning against the counter. Without another thought, he pushed off, heading for Dean’s room. Even stepping into Sam’s room had been a breach of privacy, but he had to know what else he was working with here. While Sam and Dean had worked with the Avengers and spent some down time with them, the past few months had been sparse with information. The superhero team hadn’t exactly been unbusy with everything going on in the world, but they’d tried to remain in contact with Team Free Will as much as possible. But like with his teammates, he felt he needed more input to be able to help them now. 

The door to Dean’s room was closed, which was not surprising. Taking a deep breath, he turned the knob and pushed the door open, revealing the dark room within. Reaching inside with one hand, he clicked on the lights, revealing Dean’s frankly awesome weapons display above his bed. While Sam’s room had been clear of personalization excepting his research, Dean’s clearly spoke of someone who had made a home here. There was soft lighting, magazines, personal touches hear and there, including a notepad by the bed with a bible on top of it. The bed was made, but rumpled, as though something had laid upon it and then gotten up without straightening the fabric. 

Tony sighed, then stepped back out of the room, turning off the light and pulling the door closed again. Back in the kitchen, he downed one cup of coffee, then made another, before finding and filling two thermoses to take to Sam and Clint. He was just rounding the corner to the dungeon when Dean’s words that carried into the hallway made him pause. 

“For all you know, you could be killing me.” Tony shook himself, then stepped back into the room, noting that Sam glanced his way, but both Dean and Clint completely ignored his coming. 

“Or…you’re messing with me. Either way, the lore doesn’t say anything about exceptions to the cure.” Sam tried a smirk of his own, as though he’d caught Dean in a ‘gotcha’ moment. But Dean only chuckled.

“’The lore’. Hunters. Men of Letters. What a load of crap it all is!” Dean watched as Sam’s smirk faltered. “Oh, you got nothing?” Sam turned his back to fiddle with the row of still full syringes.

“You want me to debate you? This isn’t even the real you I’m talking to.” Tony put his coffee cup and the two thermoses on one of the shelves before he stepped back into the suit, allowing it to close around him everywhere except the faceplate. He felt much safer like that. 

“Oh, it’s the real me all right. The new real me. It’s the me that sees things for what they really are.” Sam glanced up at Tony before turning back to face his brother, gathering his courage. “Winchesters. Do-gooders.” Dean scoffed harshly.

“Heroes,” Tony said. “That used to mean something to you.” Dean turned his green eyes (when had they switched back?) towards Tony, but not his head.

“Heroes.” He snorted, then shook his head, finally turning to gaze directly at Tony. “Fighting the natural order. Let me tell you something. Guys like me, we are the natural order. It’s the way it was set up.” Sam shook his own head, long hair falling forward with the movement, causing the man to brush it back behind his ears as he responded. 

“But guys like me, like us, still got to do what we can.” Dean smiled widely, but his eyes were cold as they turned back on his tall brother. 

“Don’t be so full of yourself, Sammy. ‘Cause, see, from where I’m sitting… there ain’t much difference from what I turned into to what you all have always been.” Sam froze and blinked hard. It was one thing they’d had to live through before, Sam believing himself a monster, that he deserved all the bad that came his way. He’d finally started believing that he might be worth something, that he deserved better and Tony knew this would be a setback. 

“And what exactly is that supposed to mean?” Dean leaned forward as though sharing a secret.

“I know what you did when you went looking for me.” Tony’s head jerked towards Sam, who was swallowing hard, but staring at Dean in shock. It appeared that Clint hadn’t moved at all. “I know how far you went. Crowley told me all about it. So, let me ask you…which one of us is really a monster? Hmmm? Do they know?” Dean jerked his head towards Tony and Clint. Sam’s eyes dropped to the ground and he let out a breath as he sagged against the table. “You were trying to get a 20 on Crowley and me from any demon you could snag, but Crowley didn’t want to be found and no one showed when you summoned. But you found a way, didn’t you, Sam?”

Sam’s eyes closed and his trembled, remembering talking the guy into summoning a demon to make a deal for him, promising the guy that nothing would go wrong, but the guy had been surprised when the demon actually showed and had been so excited that he’d done the deal before Sam could spring from his hiding spot and stop him. Sam had made it in time to capture the demon, but the deal was done and the man’s soul was sold. It had eaten him up inside, but he’d pushed all that self-loathing aside to focus on finding his brother. 

“I never meant-,” Sam said with a shaky voice. Dean growled.

“Who cares what you meant?! That line that we thought was so clear between us and the things that we hunted, ain’t so clear now is it?” Dean chuckled darkly. Sam opened his eyes again but couldn’t face either of the Avengers, who were now switching between watching Dean with caution and Sam with concern. “Wow. You might actually be worse than me! I mean, you took a guy at his lowest, used him, and it cost him is life and his soul. Nice work.” 

Tony gasped, then Sam moved faster than any of them expected, diving into he circle and plunging the next syringe into Dean’s neck. The older hunter roared and screamed in pain, snapping his teeth at his brother as he backed away, tossing the syringe onto the table, before turning and leaning over it, face and posture filled with pain and regret. But Dean wasn’t done. 

“Let me ask you this, Sammy. If this doesn’t work, we all know what you got to do to me, right? You got the stomach for that, Sam?” 

With that, Sam stalked out of the room, head high, not breathing until he’d stepped out into the hallway. He stopped around the corner, leaning his head against the wall and heaved in shaky breaths. He swallowed a few times, standing against the wall, head down, forehead pressed to the cool wall. He flinched when he felt a hand on his back, gently touching him. He blinked hard, then turned his head just enough to see Clint standing to his side. 

“Hey, are you okay?” While Clint was more Dean’s friend, he felt for the taller man and knew how he was feeling. His own past was full of betrayals, failed missions, torture giving and receiving, as well as internal turmoil. Sam sighed deeply before turning to lean his back against the wall, Clint’s hand falling back to his side. 

“Look, it…it’s not like it was with Crowley, during the Trials. Dean is in pain. I mean, he’s in bad pain. It’s like he’s barely holding on. I might be killing him.” 

“You might be.” Clint said bluntly. Sam looked at the dark blond agent, thinking about some of his past that Tash had shared with him. He understood it better but it didn’t solve his problem. He furrowed his brow.

“So…what do you think I should do? Should I stop?” Clint shrugged one shoulder. 

“And do what? He’s not possessed. Exorcism won’t work. Isn’t this ritual the only treatment you’re confident in? Isn’t that what you told us earlier?” Sam laid his head back more forcefully than he’d meant and rolled his eyes up to the ceiling. 

“I wish Cas was here and back to full angel power. I hate that I could be killing my brother.” Clint sighed gently before turning to lean against the wall next to Sam.

“Sam, he’s not your brother right now.” Sam gulped and nodded. Clint hated having to ask but he did anyway. “Are you prepared to have to?” He waited until Sam turned to look him in the eyes. He could see the anguish, the horror, the loss. 

“To kill my brother.” It wasn’t a question, more a statement of what he knew he might have to do. Clint brought up one hand and squeezed Sam’s elbow gently, before pushing off the wall and heading down the hall for the bathroom, going to make good use of this short reprieve from guard duty. 

“Sam?” Tony called from inside. Sam pushed off and quickly returned to the room, where Tony was pacing nervously outside the circle. “Hey, he just fell forward like that.” The distraught hunter saw that Dean was leaning forward, as though unconscious and didn’t look as though he were breathing. The tall man knelt next to the chair and gently slapped Dean’s cheeks. 

“Hey! Hey! DEAN! Come on, man! Don’t leave me. Come back.” Dean’s head moved slightly and his voice came out in a whisper.

“No.” Sam leaned back to catch his breath.

“Hey, you there? Hey!” Tony had Jarvis run his vitals but they didn’t know the baseline for a demon so it was pretty useless, he felt. 

“Dean, you okay?” Tony called to him. He wanted to go over and help Sam revive him more but he wasn’t sure the suit wouldn’t interfere with the seal or any of the ritual as only Sam had been involved or within the circle since it began. 

“Yeah,” Dean huffed softly. “If you consider drowning in your own sweat while your blood boils ‘okay’.” He coughed weakly and Sam stood up, backing away, running his good hand through his hair.

“Look, I can’t stop this now.” Dean coughed again.

“Sure you can. Just stop! There’s no point in trying to bring your brother back now.” Sam huffed angrily.

“Oh, I will bring him back.” Dean raised his head and glared at Sam.

“In fact, your uh, guilt-ridden, weight-of-the-world bro has been MIA for quite some time now. But I’m loving the new model: lean, mean, Dean.” Tony had stopped pacing to stare at Dean with his own smirk.

“Right, like you’re happy to be this and be away from your brother?” Dean whipped his head around to Tony with a laugh.

“You notice I tried to get as far away from him as possible?” He turned back to Sam and snarled. “Away from your whining, your complaining.” Sam flinched. “I chose the King of Hell over you! Maybe I was just tired of babysitting you. Or always having to yank your lame ass out of the fires since..,” he chuckled again. “Forever. Or maybe…maybe it was the fact that my mother would still be alive if it wasn’t for you.” Sam’s eyes went wide and took on a hazy gleam. Honestly, he’d already blamed himself for all of those things for the longest time, but it was the first time Dean had ever expressed his agreement. “That your very existence sucked the life out of my life!”

Tony was in paralytic shock. This Dean was a complete opposite to the man that had begged the Avengers to save his brother all those months ago. That Dean had offered up his own life in exchange for even a chance to help Sam. That Dean had been funny and charming and arrogant. This Dean was cold, hateful, outright mean. One might say, evil. And poor Sam, with his low self-esteem, was soaking up every hateful word. He appeared to wilt a little under the onslaught.

“This isn’t my brother talking.” The affect was emotionless, as though he were holding back the floodgates. 

“You never had a brother!” Dean was laughing roughly now. “Just an excuse for not manning up. But guess what? I quit.” His laughter cut off and he just narrowed his eyes at his brother, as though daring him to respond. It was, however, the change that settled Sam, that made him step forward, pointing at Dean.

“No! No, you don’t. You don’t get to quit. We don’t get to quit in this family! This family is all we have ever had!” Sam’s mouth was set into a thin line of anger. Dean looked around the room.

“You have a new family. We ain’t nothin’.” Tony was able to move again and he moved closer to Sam’s side.

“Would you say that to Dad?” Sam asked. Dean rolled his eyes.

“Dad? Oh, there’s a prize. There’s a man who brainwashed us into wasting our lives fighting his losing battle!” Sam chuffed, then turned away to get the next syringe. “Ooooh. Is this you, manning up?” Sam turned to face him again and stomped into his space again.

“This is me,” he said, jabbing the needle into Dean’s arm, pressing down the plunger, “yanking your lame ass out of the fire.” Dean began to gasp, but this time, Sam turned and walked out of the room, trying not to appear to be fleeing. Tony startled but turned to follow Sam out, pulled the dungeon doors closed behind them, feeling pretty sure Deanmon was secure inside. He had to talk to Sam.

**Notes for the Chapter:**

> Coming soon! Chapter updates at least every other week. Trying for sooner, but you know, work, life, blah, blah, blah. 
> 
> Dean tries to kill Sammy. Cas and Thor return. The cure isn't the cure-all. 
> 
> More whump and angst to come!


	5. What Was Missed

**Summary for the Chapter:**

> Summing it up

“Where’s the arc reactor?” he asked quietly from where he sat at the library table, glass of whiskey halfway to his lips, eyes full of concern. Tony smirked and shook his head. Leave it to Sam to deflect what he knew was coming.

“Okay, but then we’re going to talk about you and Dean.” Sam nodded and gave him his full attention. Anything to get his mind off all the horror in his own life. “Don’t know if you guys saw it on the news or whatever, but the terrorist, the Mandarin? Turns out he was this scientist named Killian who subverted that new regenerative treatment called Extremis to his own nefarious purposes. Killian wanted revenge on me because I rejected his offer to work with him.” Tony poured himself a glass of whiskey before joining Sam at the table.

“He was testing on veterans. It was helping people, but it made them super strong too, if only temporarily, because Extremis was extremely unstable. They exploded, literally, if they couldn’t control their emotions. He was using them to kill innocents by making them living bombs. Happy got hurt, but he’s doing better. Then the bastard kidnapped Pepper and injected her with it. Pepper was already upset with me because my PTSD was keeping me up at all hours of the night.

“Anyway, Pepper wanted me to scale down the project but I couldn’t do it. I tried to save her and it almost killed her, myself, and the president. You know I’d do anything for her so I blew up all my extra Iron Man suits for her and that kept her stable enough that she saved my life and her own, but she killed Killian. So long story short: Pepper is the hero, the Extremis burned itself out of her safely, and she talked me into facing my fear and having the shrapnel removed so I don’t need the arc reactor anymore.”

Sam just stared at him for a moment before nodding.

“I’m glad you and Pepper worked that out,” was all he said. Tony smiled with his head cocked a little. He downed his drink, then turned the glass this way and that as he addressed Sam.

“Yeah, me too.” Tony sat back and eyed the taller hunter, taking in how he’d started looking worse over the past few hours, not better. “Now, you know the demon side of Dean is just using all your insecurities to make you pause, make you make a mistake. That’s not really your brother in there. You know that, right?” Sam stared at the amber liquid in his glass a moment.

“But it is. Yeah, I know what he’s doing. I know it’s stuff he’d never say if he wasn’t a demon, but that’s Dean. That’s my brother.” Now it was Tony’s turn to turn the conversation. 

“We didn’t get to talk in depth before beyond making the plan to get your brother back. So how did Kevin die?” Tony prodded. Sam swallowed the last of his drink as well. He stared at the empty glass, glancing longingly back at the whiskey bottle across the room for a moment before sighing, running a tired hand over his face.

“Do you remember Dean telling you about that angel, Gadreel?” was how he started. Tony thought back and frowned. “The name you knew him by was Ezekiel.”

“That angel that responded to Dean’s prayer and tried to trick him into possessing you?” Tony asked. Sam nodded, closing his eyes.

“He lied. Cas told us later. Gadreel apparently was working for Metatron. He lied to Cas and told him he was wanting our help because he couldn’t watch what Metatron was doing anymore and he was willing to work with us on the sly to stop or kill him if need be. Turns out it was all another trick. Once we started getting comfortable with letting him into the bunker, he got caught by Kevin stealing the angel and demon tablets. He, uh, killed Kevin. He…he burned him out.” Sam sniffled but didn’t let any tears fall. “We, uh, burned Kevin, gave him a hunter’s funeral, so he could go to Heaven and be at peace.”

“Damn, I liked that kid.” Sam gave him a brief smile in thanks.

“You know that Cas has been working with Thor to find a way to defeat Metatron or at least reopen Heaven for the other angels to be able to return.” Tony nodded and shrugged. “Cas being human made it hard for him to do anything but he was still working to save Heaven and his brothers and sisters. Not sure if you knew that Thor’s people had found a potion that mimics angel grace but the supply is limited and it fades away over time. And only angel vessels, ones that have hosted angels’ grace before, could use the potion.”

“That, I did not know,” Tony said in surprise. Thor had been extra anxious lately, worried about his angel friend and having to continually provide the potion. Sam nodded.

“Yeah, it was great. Cas was Castiel again. He could smite, heal, hear angel radio again. Turns out the more he used the faux grace, the faster it wore off, so he started using it sparingly, only when it was really dire, because the supply came from some really rare plant on Asgard. Thor’s people weren’t holding out or anything but the making of the potion was so complex and time consuming that it wasn’t feasible for Cas to go back to acting like a full angel again.

“We helped Cas capture Gadreel so we could stop him. Metatron had him killing off angels that wouldn’t bow to his will…and the prophet.” Sam took a long, deep breath. “We didn’t find the tablets, but Cas said he was going to use Gadreel as a bargaining chip to get an audience with Metatron in Heaven. We had figured out that the tablets were giving him his godlike powers and he would obviously keep them locked in Heaven so no one could get to them. He had also talked some of the angels into working for him, only allowing them back into Heaven with him, and he convinced them that Castiel really was a traitor. Last time I saw Cas was a few weeks ago, when he left with Gadreel in enochian handcuffs to try to talk to Metatron and the other angels.”

Tony leaned forward with a smile.

“I know you’ve been focused on Dean but Thor found Cas. His temporary grace was failing again.” Sam looked at him with sadness and concern. Tony held up his hand to stop him. “Thor’s mom found a sorceress on another one of the other planets in the Nine Realms and had worked it out for a permanent solution potion that would give him his powers back permanently. Cas really didn’t want to leave you and Dean behind but as we were on our way, Thor was able to convince him he’d be better able to help once his grace was fully restored. So that’s where they are. Supposed to be back in a few days.” 

Sam stood and paced a little, heaving deep breaths. He stopped and dropped back into his chair so he wasn’t looming over the billionaire. He leaned forward earnestly.

“Thank you. Thank you! I’ve been so worried about losing Cas if I didn’t save Dean in time.” The darker haired man nodded thoughtfully. 

“Well, with Steve and Natasha on their hunt for Bucky the Red and whatever the hell is going on with SHIELD, and Bruce stuck dealing with that outbreak, we couldn’t just leave you guys hanging. Between all of us, between saving the world and stopping alien and monster takeovers, curing one angel and one demon shouldn’t really be that hard, right?” Sam barked out an unexpected laugh before leaning back again. Some of the tension bled out of him. 

“Right…,” Sam sighed after a few minutes. “Well, I’m pretty confident that Thor’s got Cas’ issues in hand and we have enough purified blood to do this ritual a few times over, so let’s go see if we can get this show back on the road.” They both stood, turning to head back to the dungeon, when Crowley and two demons appeared in front of them.

“Moose, how’s your little problem coming along?”

“Crowley, you smarmy bastard!” Sam growled, tensing into an attack stance. Tony went on alert and narrowed his eyes.

“And look, Sam, he brought stunt demon #1 and stunt demon #2.” Both of the demons smirked at him, leaving Sam to the boss.

“You’re not so tough without your suit, Iron Ass,” the one of the left said. 

“Hey,” a voice rang out from the hallway door. “No one calls him that but me.” Clint was standing just outside the library, using the doorframe as leverage, his bow nocked and aimed. He tilted his head slightly and grinned sideways. “And sometimes Nat when she’s tipsy.” 

Crowley rolled his eyes but never took his gaze off of Sam.

“Nice to see your friends are still hanging around.” Sam clenched his good fist.

“You aren’t getting him back,” He growled between gritted teeth. Crowley chuffed out a laugh, holding up his hands to stop his demons from moving in. 

“Don’t want him. Don’t need him. But I think we can agree he and the precious cannot be in the location anymore.” Sam blinked in confusion before it dawned on him that he was talking about the First Blade. Sam shifted his stance, using a hand motion to let Tony and Clint know to not make a move yet. 

“What are you going to do with it?” He eyed the King of Hell to gauge his intentions.

“I don’t know. Throw it in a volcano, leave it on the moon, whatever I want to be sure it’ll be out of reach of our favorite flannel-wearing demon. I can put it places he’ll never be able to get to.” He waved a hand dismissively. 

“Thor can get it so much further than you can reach,” Tony smirked at him, still watching the two demons closely. Crowley looked around.

“I don’t see him around here and it’s extremely dangerous to keep it and him-,” he thumbed behind him towards the dungeon, “too close together. Should your brother get free before you cure him, I don’t give much for your chances.” He huffed when Sam still hesitated. “Honestly, Sam, you know it’s just an ass’s jawbone in anyone else’s hands. Even mine.”

Sam finally made up his mind and headed to his room for the sealed curse box. Clint raised the nocked arrow away from Sam as he passed by him in the doorway, but it immediately returned to cover Crowley and his minions. Tony remained by the table, Jarvis on alert to bring the suit from outside the dungeon if any of the three made a move. It was a tense few moments before Sam returned, carrying the First Blade, wrapped in a tattered black cloth. Crowley turned to face him with a pleased smile and reached for it. The tall hunter pulled it back before he could latch on.

“This is only because of my brother. I still don’t trust you.”

“You’re breaking my heart, Samantha. You don’t have to trust me. Just trust I don’t want this thing and your brother together right now any more than you do.” The demon King kept his hand out and raised an eyebrow, waiting patiently for Sam to hand it over. Sam sighed deeply, then relented, laying the bundle in his hand. Just as the cloth fell back a bit and the tip of the jawbone was revealed, a chilling sound echoed from behind Clint.

“Oh Saaaammmy! Come hang out with your big brother!” All of them froze. It was obvious to everyone there that that voice had not come from the dungeon. It was much closer. Dean Winchester, demon Knight of Hell, was free in the bunker.


	6. A Knightly Battle

**Summary for the Chapter:**

> Will Dean get cured? Will the Avengers be able to stop him again now that he knows their tricks?

“Bollocks!” Crowley growled, snatching the blade and poofing out, quickly followed by his minions. Clint had whipped around and had his bow pointed down the hallway, scanning for the terrifying figure to come into view. Tony pressed the button his wrist cuff, summoning the suit to where he stood, tenser than when the demons had appeared. Sam, however, was wide-eyed, mouth open, heart racing. 

“Come on, little brother, don’t you want to spend a little quality time together?” The taunting voice carried around the corner, getting closer. The Iron Man suit wooshed past Clint and wrapped Tony up quickly. 

“Sam?” Clint asked without turning his head. 

“Uh,” Sam started, pulling out the demon knife to hold it defensively. “I’ll get the bunker locked down, if you guys can get behind him and make sure he can’t leave through the garage. Try not to kill him since I think we’re close to finishing the cure.” Clint gave a barely there nod to compliment Tony’s huff of agreement. 

Once Clint had given the hand signal for coordination of movement, Tony slipped down the hallway towards the armory and firing range and Clint disappeared around the corner that would take him to the garage to secure that exit. Sam took a few deep breaths to steady himself before he padded up the stairs towards the computer room, where he knew the bunker’s master keyring lay at the bottom of one of the drawers. Keeping his awareness open from all sides, he silently slid the drawer open and wrapped his large hand around the keyring, trying to keep them from rattling as he lifted them out and shut the drawer. It was a tense moment as he rushed down the far hallway towards the electronics room. He knew he’d turn a corner any minute and it could be the end of either him or his brother. 

So intent on getting to the electrical room was Sam that he didn’t realize Dean was in the kitchen. Surely he’d already looked around for the First Blade and was now searching for a lesser replacement. But Dean’s eyes slid to black as he bypassed the large carving knife and grasped the old-fashioned hammer instead. He sighed around the dark smile and turned away to continue his taunting. 

“Tony, Tony, Tony. Your suit may protect you from my demon powers for the most part, but you can’t save Sammy from getting what’s coming to him. You might as well back off and just leave us to playtime.” No one answered him so he continued down the hallway, kicking in doors, all the while looking like a man on a mission. 

Sam panted as quietly as he could as he finally reached the electrical room. He deftly used a key to get in and darted over to shut off the bunker power system, throwing the bunker into emergency lockdown, which would at least slow Dean down a little. The red emergency lights flashed and the sirens blared in a subdued tone. Sam sighed in accomplishment. Tony smirked at Sam’s cleverness. Clint didn’t flinch but appreciated the lack of lighting that would aide his stealth. 

Dean laughed harshly because he now knew where his brother was. He stepped faster, never breaking the purposeful, bowlegged gait he was using. 

“Smart, Sam! Locking the place down. Doors won’t open. I get it. But here’s the thing. I don’t want to leave. Not ‘til I find you.” He rolled towards the electrical room. “You’re just making this worse for yourself, man!” He turned the corner to the room and the door is partially ajar. His smile now shows his teeth, bared, vicious. “Oh, by the way, you can, uh, blame yourself for me getting loose. All that blood you pumped into me to make me human? Well, the less demon I was, the less the cuffs worked. And that Devil’s Trap? Well, I just walked right across it. It smarted, but still.” 

Dean, gripping the hammer in his right hand, where the Mark stood out, a flaming red, reached the shutdown switch and pulled it back up. Instantly, the sirens quieted and the lights in the bunker changed from the blinking red to the steady white. Sam looked around and darted towards the door where he had hidden down a side hallway.

“Now that’s more like it,” Dean nodded to himself. He turned his head as the door slammed shut behind him and he heard the key being turned in the lock. “That’s your big move?” Sam tossed the keyring onto the floor and brandished the Kurdish blade before addressing his brother through the door.

“Listen to me, Dean! We were getting close, okay? I know you’re still in there somewhere. Just let us help you. We can finish the treatments.” When there was no answer to his plea, he grew antsy. “Dean?” The next heartbeat jumped and began to race as the door was slammed against and began to splinter. He was aghast as he watched the door breaking under the onslaught of Dean’s demon attack with the hammer. 

“You act like I want to be cured!” Once the whole in the door was large enough, Dean eyed his brother through the gap and grinned, causing Sam to swallow and take a step back. “Personally, I like the disease.” He pulled back the hammer and once again wailed on the weak wood of the locked door, throwing splinters everywhere. Sam held out the blade nervously.

“Dean, stop that! Look, I don’t want to use this blade on you!” Dean paused long enough to lay his head back for a deep laugh, much colder than his usual one. 

“That sucks for you, doesn’t it? ‘Cause you really mean it.” Sam gulped, taking another step back. The blade wavered as he nervously faced his brother. 

“If you come out of that room, I won’t have a choice.” Dean leaned his face through the larger opening, smirking condescendingly.

“Sure you will! And I know which one you’ll make. Isn’t that right, Sammy? But see…here’s the thing. I’m lucky. Oh hell, I’m blessed. ‘Cause there’s just enough demon left in me that killing you ain’t no choice at all. And killing Tony and Clint? Just a bit of revenge for helping you cage me.” He kicked through the last part to make an opening large enough to fit through, causing Sam to turn and run full tilt around the corner and away. 

“Sammy?” He stepped into the hallway, head lowered as he listened for the sounds of his fleeing brother. Once he had the direction, he smiled widely and turned that way, head swinging up, leading his body. “Let’s have a beer, talk about it. Isn’t that always what you want to do? Talk about it? But I’m tired of playing. Let’s finish this game!” 

Around the next corner, Sam stopped and was leaning against the wall, cradling his injured arm with the other arm, blade resting against the outside of the sling. He was heaving in a few breaths as he leaned around the corner to see if Dean had caught up yet. He thought he caught a glimpse of the Iron Man suit but couldn’t be sure as it was too fast. Turning back, feeling something behind him, hoping it’s Clint, he heard the swish and ducked. The hammer Dean had brought around to smash into his head landed a glancing blow, throwing Sam to the ground, blood beginning to drip into his eyes where his vision was already blurring from the hit. 

Sam rolled quickly to bring the blade up to protect himself. Dean tried to pull the hammer from the wall but smirked with an idea and leaned forward into the blade instead. 

“Well, look at you. Do it. You said you would. It’s all you, little brother.” Sam really only had to press forward and the blade would have slid in, ending the demon, but even if he wasn’t blacking out, he couldn’t kill his brother, so he let the blade drop before he dropped his head to the floor, closing his eyes in defeat. Dean laughed and stepped forward to grab Sam by the shirt to yank him up, but suddenly Iron Man was hovering at Sam’s head, forcing Dean to look up, his face full of rage. 

“Step back, Dean.” Tony held out his hand, aiming a repulsor beam at the black-eyed man. He already had Jarvis scanning Sam but wasn’t taking his eyes off the demon. Dean scoffed, but with a glance down at the nearly unconscious man hanging from his hands, he threw him back to the floor and stood up to square his shoulders against the Iron Man suit.

“And just what do you think you can do to me? I don’t see Clint or any of his fancy arrows to help you.” He shrugged, then yanked the hammer out of the wall. Tony smiled inside the suit.

“The thing about Clint is that he’s deadly when you can see him, but he’s more deadly when you can’t.” Dean frowned and tilted his head, just as he heard a swish and felt electricity flood his body. Iron Man reached down to pull Sam backwards out of the way as dean twitched under the taser arrow onslaught. Dean twitched hard but growled and then reached around to yank it out of his back, breaking the contact and stopping the flow of the electricity. He threw it down and turned to face the archer, who was kneeling at the far end of the hallway, another arrow nocked and ready to go. Dean roared and stalked towards him, picking up into a run. The next arrow released by Clint hit Dean in the thigh and again, the electricity made him pause and he fell to his knees, twitching. 

Again, Dean regained enough control to yank out the arrow and break the taser effect, but before he’d taken another step towards Clint, a pair of strong arms came around him and halted his progress. He tried to yank away, roaring more. His arm came up with the hammer but it was knocked away by a tsking Thor, who stood before him shaking his head in sorrow. 

Dean roared at Thor, shaking in rage. The arms around him tightened. 

“It’s over,” came the gravelly voice of Castiel, who was now gripping the demon tightly. Dean roared and twisted to no avail. 

“Dean, stop, it’s over.” Cas continues to hold him and looks over his shoulder to where Tony is cradling a now awakening Sam. 

Finally, Dean settled, seething, seeing the futility of his attempt to escape now that Thor and the newly repowered angel have arrived. 

*****

A short time later, they all stood around where Dean is once again strapped to the chair in the Devil’s Trap, all of them outside the ring. Clint, bowed laid at hand on the table beside him, applied a bandage to Sam’s head, while Tony tried to talk sense into him.

“Sam, once again, you’ve taken a blow to the head. This last treatment can wait until you’re not seeing two of everything.” Sam shook his head, wavering a little. Thor reached out to hold him steady. 

“Sam, let me heal your wound,” Castiel said, reaching for him. Sam batted his hand away.

“Once this is finished, Dean may need the help. Save the power for him. I’ve survived worse. You can heal me after I know he’s back to normal.” Castiel huffed and crossed his arms but nodded. Thor was staring at Dean with sadness.

“My warrior brother has been brought so low as to try to kill his own brother.” 

“And us,” Tony chimed in, raising a hand and indicating Clint and himself. Clint smirked.

“Tony, even I’ve wanted to kill you before. It was just Dean’s turn.” Sam chuckled as he pulled out the last syringe and stepped into the circle. Tony mock pouted before he turned his back on Clint to monitor Sam. The tall hunter takes a deep breath as he stuck the needle into Dean’s arm, just above the Mark of Cain. As the plunger is pressed, Dean is slumped over, head hanging onto his chest. Sam pulls the needle out and returns to Cas’s side to toss it onto the table. 

“Last step.” Sam pulled the demon blade across his palm and returned to where Dean sat, nearly unconscious. Standing behind him, he had Cas tilt Dean’s head back and open his mouth. Sam placed his bloody palm over Dean’s mouth and said the final ritual words, causing the area around him and his brother to flare up for a moment before subsiding. They wiped his chin and let his head back down gently, then went back to the group to let Cas wrap his bleeding hand. Sam looked at Cas.

“What the hell are we doing to him? I mean, even after I gave him all that blood, he still said he didn’t want t o be cured, that he didn’t want to be human.” All of them glanced at him. 

“Well,” Cas began, “I see his point. You know, only humans can feel real joy, but also such profound pain. Being a demon, with no cares, no worries, it’s easier.” Clint’s eyes refocused inwards for a moment, completely understanding. Tony leaned against the table next to Sam and tilted his head, applying this bit of logic to what he knows of the Winchesters. He could honestly see the appeal after everything they’d been through, not that it was ideal, just appealing to be able to be so carefree. 

Sam scrubbed his good hand down his lower face, avoiding the bandage on his temple for now. He had closed his eyes in contemplation but they shot open again when Dean groaned. He stood up and took a step forward, reaching out to brace himself on Iron Man’s shoulder. 

“Dean?” The older hunter blinked, slowly raising his head. When his eyes opened, they were still the inky black, but as he blinked slowly, the black faded to gray, then disappeared altogether. Clint unscrews the flask that sits on the table and tosses some water into Dean’s face, where it splashes harmlessly. No demon reaction. 

“You look worried, fellas,” comes the gruff reply as Dean gives a small, tentative smile. Sam grins from ear to ear and looks around at his friends, who helped him save his brother, before rushing to begin untying him.

“Welcome back, Dean.” 

“Yeah, welcome back, douchebag.” Tony mutters with a smile. They’d done it and they were all tired but elated. 

It was some time later, after showers, and nervous hugs between the brothers, that the Avengers began to pack up for their trip home.

“You sure you don’t need us to stick around?” Tony asked, glancing towards the doorway that led to the hall that led to where Dean lay in his bed, resting. Sam waved his previously injured hand dismissively.

“Nah, you guys really helped and he’s a little out of it, but better, I think. I mean, I think this whole thing, the blood cure and the …well, all of it, really wrecked him, you know? And I have Cas here now and he’s powered up again,” He pointed to his head which was now unmarred and then flexed both arms, rolling his shoulders to demonstrate that Cas had healed him perfectly. Tony nodded, then clapped Sam on the shoulder. 

“So, where are you going?” Thor asked, seeing that Sam had car keys and a jacket in his hands. 

“On the plus side, he’s hungry again, so I’m just going to go pick him up a big old bag of crap food and stuff it in his face myself. You mind keeping an eye on him until I get back?” He asked Castiel, glancing at him over Thor’s shoulder. Tony smirked that Sam was tall enough to do that as no one else he knew could, except the Hulk. 

Cas nodded. “Yeah, but Sam?” Sam stopped, running a nervous hand through his hair. 

“Yeah?” Thor and Tony waited patiently, no longer making the move to finishing packing up. 

“You realize that one problem is solved, but one still remains.”

“The Mark,” Thor said quietly, frowning. 

“Yes. Dean is no longer a demon, but sooner or later, the Mark is going to be an issue.” Cas was frowning himself, looking from face to face to gauge their reactions. Sam sighed deeply and then replied in a very tired voice. 

“You know what, Cas? I’m beat, man. One battle at a time, you know? So, I’m just gonna go grab my brother some cholesterol. And then, I’m going to get drunk and sleep.” Cas nodded in understanding. 

Thor accompanied Sam to get the food and alcohol, leaving Cas and Tony to finish packing and watching the bunker. 

In Dean’s room, Clint leaned against the doorframe and watched Dean flip through the only photographs he had of his family. He stopped at the one of him and Sam laughing at some silly thing that Bobby happened to capture with his camera. He ran a thumb over his brother’s face gently. 

“You look terrible,” Clint said with a smile. Dean laughed roughly. 

“You know, I thought spies were supposed to lie.” He tucked the photographs back into the bible where he’d had them hidden before turning to lean against the headboard on the bed and face the archer. 

“We lie when it’s necessary,” Clint shrugged. “Really, you look like death warmed over.”

“That’s an understatement.” Dean swallowed. “Look, uh, I want to thank you guys. Again.” Clint stood straighter and stuck his hands in his back pockets. 

“Not a scratch on us, so don’t worry about us. Just glad Thor and Cas got back when they did.” Both heads swiveled when Cas stepped through the door, past Clint. 

“So, are you back?” Dean asked his angel friend.

“At least temporarily. The Asgardians have a potion that mimics grace and it will last a very long time as long as it’s not used too strenuously. They are still looking for something more permanent or a way to locate my stolen grace. And a way to reopen Heaven properly. They have been most hospitable.” Cas shrugged in a very human way. Clint smiled.

“Yeah, Thor’s good people.”

“So, um,” Dean began, glancing down at his hands before looking up at Cas again. “What did Sam say? Does he want a divorce?” Cas tilted his head.

“I’m sure Sam knows that whatever you said or what you did, it wasn’t really you. It certainly wasn’t all you.” Dean huffed.

“I tried to kill him.”

“But you didn’t,” Clint pointed out.

“If you guys hadn’t been there, I might have.” Clint shrugged then, again leaning on the wall. Castiel looked between them before settling back on Dean.

“Dean. You two have been through so much. You’re brothers. It’d take a lot more than trying to kill Sam with a hammer to make him want to walk away.” Dean smirked wryly.

“Do you realize how screwed up our lives are that that even makes sense?” Clint laughed and shook his head, turning to head back to the library to meet up with Tony. He’d seen what he’d needed to see.

After he was gone, Dean stood up and came closer to Cas. 

“I’m glad you’re here, man.” Cas gives a faint nod before turning away. Before he can exit the room completely, he turns back. 

“Maybe you should, um, take some time before you get back to work. Allow yourself to heal. It’s, uh, I don’t know. The timing might be right. Heaven and Hell, they seem reasonably back in order. It’s quiet out there.” Dean nods and lifts his hand in a waving gesture of acknowledgement as Cas returns to the library.

Later still, Sam and Thor returned with bags of greasy food for Dean and several cases of beer for whoever wanted one. Clint had merely shook his head with a laugh and clapped Sam on the shoulder before heading up the stairs with his bowcase. Thor had followed him out after a forearm grasp with both Sam and Dean. Tony had lagged behind to get a final glimpse at the new and improved human Dean Winchester before finally heading out to meet his teammates at the jet and return home.

Cas had escorted Dean to the kitchen, where Sam had laid out the food and some beers and as soon as Dean had appeared nervous in Sam’s presence, his younger brother had swept him into a huge hug, patting his back. 

“I’m glad you’re back, Dean.” Dean had hesitated only a moment before gripping him back just as hard, smiling with watery eyes that his little brother, the one he’d nearly killed, had forgiven him so easily. Sam said nothing about the impending tears, but only pushed the food towards Dean, along with a beer, and began regaling him with stories about Tony’s arc reactor and what was going on with the rest of the Avengers, steering clear of discussion of the Mark for now. 


	7. Book 4 Teaser

Teaser for the next installment:

Sure, Ultron was Tony’s brainchild, but when there’s world ending chaos around the corner, who else but the Winchesters could get involved, even though they have their own new villain, God’s sister. Saving the world has become a join team effort. 


End file.
